Our research proposal derives from the emerging association of methamphetamine (MA) abuse with rampant dental caries and involvement of tooth surfaces that are considered, otherwise, to be at low risk for decay. Commonly identified by the moniker meth mouth, these oral co-morbidities of MA use may be exacerbated in immune-compromised individuals who are at increased risk for caries and periodontal disease. Despite the manifest personal and societal impact, the lack of ecological studies and operational definitions of meth mouth have prevented the cultivation of a knowledge base to help dental professionals distinguish the condition in its early stages, formulate best clinical practices and, allow integration of the dental community in a collaborative care model for treating the health consequences of MA use. Our precursor investigation, based on physician-conducted assessments of 301 MA users, has established that extensive dental disease is a distinguishing comorbidity in MA users. Through detailed oral assessments by trained and calibrated dental examiners we now seek to validate the initial findings of our physician assessors and evaluate the discriminant utility of oral/dental manifestations for detecting and managing undisclosed MA users presenting to the dental office. We hypothesize that the rates and patterns of dental caries experience and oral disease in MA users will be significantly different than a propensity-score matched cohort of individuals from the National Health and Nutrition Examination Survey (NHANES) and reflect the severity of the MA use behavior. Using a cross-sectional survey of 500 adult MA users, we will: 1) validate that the rates and patterns of dental caries experience and oral disease are substantially different in methamphetamine (MA) users than non-MA users; 2) characterize the relationship between dental consequences, patterns of MA-use and other individual characteristics; 3) develop a composite index of dental disease, based on a detailed pattern of dental caries experience, that can help dentists reliably distinguish covert MA users from non-users; and 4) investigate the extent to which negative dental self-image among MA-users is associated with a willingness to seek treatment. A key goal is to summarize and disseminate our research findings through a web based, queriable, repository of indexed digital images documenting the range of oral manifestations and their association with the levels of MA use. Understanding the oral consequences of MA use and the contextual sociobehavioral determinants will help dental professionals distinguish the condition at an early stage, develop best practices for managing the consequences, and set the stage for targeted prevention and intervention strategies that meaningfully involve the dental community in the healthcare of MA users.